A N-tert-butyl-2-pyrazinecarboxamide is a known compound, and reactions in which this compound is used as a starting substance are already known. There is, however, no report concerning a process for preparing a N-tert-butyl-2-pyrazinecarboxamide.
Also, it is shown in Japanese Unexamined Patent Publication No. 117869/1989 that a N-tert-butyl-2-piperazinecarboxamide, which is one of the compounds obtained by the preparation process of the present invention, can be obtained by hydrogenation of a N-tert-butyl-2-pyrazinecarboxamide.
However, in the above-mentioned process, expensive platinum oxide is used as a catalyst, and the reaction of hydrogenation has to be performed under the high pressure of 100 atm (1.01.times.10.sup.4 kPa) for 6 hours; therefore, the process is not necessarily advantageous for a manufacture on an industrial basis.
An object of the present invention is to obtain a N-tert-butyl-2-pyrazinecarboxamide, which is useful as an intermediate of medicines, in a high yield. The other object of the present invention is to provide a process for preparing a N-tert-butyl-2-piperazine-carboxamide which is useful as an intermediate of medicines by performing hydrogenation of a N-tert-butyl-2-pyrazinecarboxamide under economical and industrially advantageous conditions.